Field of the Invention
The present invention relates to the use of special amino-triazine based Mannich-compounds for increasing the resistance of organic material, preferably polymer, against degradation caused by oxidation; to organic material, preferably polymers, with increased resistance to oxidation and to the use of the polymers, with increased resistance to oxidation for producing articles.
Description of Related Art
It is known that the mechanical, chemical and/or aesthetic properties of inanimate organic materials, especially of polymeric materials, worsen under the influence of energy such as heat and/or sunlight and other sources of ultraviolet (UV) radiation, and/or oxygen. This results in an irreversible deterioration of the chemical and/or physical properties of the non-living organic materials, e.g. results for polymeric materials i.a. in a loss of strength, stiffness and flexibility, discoloration and scratching and loss of gloss.
Such aging processes are normally based on oxidation reactions which are caused by heat, light, mechanical stress, catalysis or reactions with impurities. The aging of polymeric materials can occur during their production, during processing into shaped parts by moulding, extrusion, etc. and/or during use of the shaped parts.
It is well-known in the art that stabilizers, such as antioxidants and light stabilizers can prevent or at least reduce these effects by adding them to the polymers to protect them during processing and to achieve the desired end-use properties.
Stabilizers, like antioxidants, traditionally and currently used comprise sterically hindered phenolics, aromatic amines, hindered amine stabilizers, organo-phosphites/phosphonites and thioethers. However, appropriate combinations of stabilizers have to be carefully selected, depending on the desired final properties, the polymeric article should have.
Antioxidants interrupt the degradation process in different ways, depending on their structure. The two major classifications are chain terminating primary antioxidants and hydroperoxide decomposing secondary antioxidants. Primary antioxidants react rapidly with peroxy radicals and are therefore called “radical scavengers”. The majority of primary antioxidants for polyolefins are sterically hindered phenols.
Low volatility is an important characteristic of stabilizers used in any applications where high temperatures are encountered. High temperatures are used in the processing of thermoplastics and in the curing of thermoset resins and coatings. High temperatures are also often present in the end-use applications for the stabilized material. Low volatility will prevent loss of the stabilizer during processing, curing, and high temperature end-uses.
Besides reducing losses of stabilizer during processing or curing, low volatility will minimize processing problems such as die lip build-up and plate-out.
Stabilizers known from the state of the art have a number of disadvantages. A major disadvantage is the frequently insufficient duration of the protective effect. A further disadvantage is the often poor synthetic accessibility of many stabilizers.
Many stabilizers migrate out of the polymer substrate to be protected, or are adsorbed (chemically or physically) by one or more systems components (such as pigments), thereby diminishing their effectiveness. Such migration and adsorption problems are examples of the general problems of lack of solubility and compatibility found for many commercial polymer additives.
Migration behavior of stabilizers added to polyolefin-based materials is dependent from a number of different properties such as diffusion rate of the molecules within the polymer matrix, chemical stability of the additives, type of additive decomposition products, etc. It has to be taken into account that an improvement in migration behavior must not be obtained on the expense of stabilization of the polymer matrix. Thus, providing an additive composition of low migration tendency is not straight-forward but rather needs a careful selection of appropriate compounds.
Thus there is still a demand for improved stabilizers, especially antioxidants which show improved properties, like low volatility, low migration tendency, high solubility, long-term stabilization, and the like.
Furthermore the antioxidant should lead to a high resistance of the stabilized polymers against oxidative degradation as measured in terms of oxidation induction times (OIT).
The object of the present invention is therefore to find suitable compounds showing all the desired properties, which can be used as antioxidants for organic materials, especially for polymers.